<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>计算圆的周长和面积</title>
</head>
<body>
    
    <input type="text" placeholder="半径" id="a">
    <input type="text" placeholder="周长" id="b">
    <input type="text" placeholder="面积" id="c">
    
    
    <script src="script.js"></script>
    
</body>
</html>